PVA-Ag / coumarin nanocomposites with different concentrations of coumarin have been
prepared and characterized. The reliance of dc conductivity on temperature has been studied in the
temperature range 303 – 393 K. The ac conductivity and dielectric properties of the
nanocomposites, have been studied in the frequency range 100 Hz – 10 MHz and temperature
range 303 – 393 K. The results depicted that electrical conductivity increased by raising coumarin
concentration. The activation energy has decreased as the content of coumarin increases up to 12
wt. %, then it increases as coumarin content increases. The ion transport number t ion of the
prepared samples have been calculated by Wagner's dc polarization method. It can be observed
that the ion transport number t ion lies in the range 0.7 < t ion < 0.91 which implies that conduction
in the samples is ionic. The study of frequency dependence of both dielectric constant and
dielectric loss showed a decrease with increasing the frequency while they increase with increasing
the temperature. The loss tangent (tanδ) depicted a peak with the frequency, which points to |
